Nuclear fuel storage facility

Abstract

A spent nuclear fuel storage facility. In one embodiment, the invention is directed to a storage facility including an array of storage containers. Each of the storage containers includes a body portion and a lid. The body portion has a storage cavity configured to hold a canister containing spent nuclear fuel. The lid, which may rest atop the body portion in a detachable manner, includes an inlet vent and an outlet vent. Each of the storage containers may be configured to draw air through the inlet vent and into the storage cavity where the air is warmed and passed through the outlet vent as heated air. The body portion of the storage containers may be positioned below grade and the lid of the storage containers may be positioned above grade.

What is claimed is: 
     
       1. A low profile system for below grade storage of spent nuclear fuel comprising:
 an array of storage containers, each of the storage containers comprising:
 an elongated body portion embedded in an engineered fill below grade, the body portion including a floor plate at its bottom, an open top end, and a storage cavity extending between the floor plate and the open top end configured for holding a canister containing spent nuclear fuel; 
 a lid positioned above grade, the lid removably coupled to and enclosing the open top end of the body portion; 
 the lid comprising a plurality of air inlet vents and at least one air outlet vent, the inlet vents each forming a passageway from the cavity to an ambient atmosphere and the at least one air outlet venting forming a passageway from the cavity to the ambient atmosphere; 
 the inlet vents comprise a plurality of discrete peripheral openings formed in a sidewall of the lid and located circumferentially around the lid, and 
 wherein the at least one air outlet vent comprises a plurality of discrete air passageways each extending from a plurality of separate bottom openings in a bottom surface of the lid which converge at a common single central opening extending through a top surface of the lid which ejects air to the atmosphere; 
 
 a top concrete pad disposed on top of the engineered fill, an upper part of the body portion of each storage container being embedded in the concrete pad such that the open top end of the body portion is positioned adjacent a top surface of the concrete pad. 
 
     
     
       2. The system according to  claim 1 , further comprising an annular radially protruding flange ring integrally attached to the top end of the body portion of the storage container above the concrete pad, the flange ring being seated on the top surface of the concrete pad. 
     
     
       3. The system according to  claim 2 , further comprising an annular container ring extending downwards from a bottom surface of the lid, the container ring laterally surrounding and peripherally engaging the flange ring of the body portion to restrain the lid from horizontal movement during a seismic event. 
     
     
       4. The system according to  claim 1 , further comprising at least one annular gasket forming a seal between the lid and body portion of each storage container. 
     
     
       5. The system according to  claim 1 , further comprising a concrete base embedded in the engineered fill, wherein the floor of the body portion of each storage container is supported on top of the concrete base. 
     
     
       6. The system according to  claim 5 , wherein the floor is anchored to the concrete base by a plurality of anchors. 
     
     
       7. The system according to  claim 1 , wherein the body portions and lids of the storage containers are each configured and arranged such that the body portion of each storage container is concealed when the lid is coupled to the body portion leaving only the lids visible at the top concrete pad. 
     
     
       8. The system according to  claim 1 , wherein the lid of each of the storage containers comprises a diametrically enlarged upper flange portion sealably engaging and radially overhanging the open top end of the body portion in a cantilevered manner, and a central lower cylindrical plug portion extending downwards from the flange portion, the plug portion being insertably received through the open top end of the body portion into the storage cavity. 
     
     
       9. The system according to  claim 8 , wherein each of the storage containers is configured to draw air through the inlet vents which extend through the flange portion of the lid and into the storage cavity, the air being heated by the canister when emplaced in the storage cavity, the heated air flowing through the plug and flange portions of the lid via the at least one outlet vent to the ambient atmosphere. 
     
     
       10. The system according to  claim 9 , wherein the inlet vents comprise a plurality of discrete circumferentially spaced peripheral openings formed in a sidewall of the flange portion of the lid. 
     
     
       11. The system according to  claim 10 , wherein the at least one outlet vent comprises a plurality of discrete air passageways each extending from a plurality of separate bottom openings in a bottom surface of the lid and converging at a common central opening extending through a top surface of the lid. 
     
     
       12. The system according to  claim 11 , wherein the discrete air passageways each have an arcuately curved shape and fluidly communicate with the storage cavity via the plurality of bottom openings formed in a bottom surface of the lid. 
     
     
       13. The system according to  claim 11 , wherein the bottom openings each have an arcuately curved shape. 
     
     
       14. The system according to  claim 11 , wherein the discrete air passageways are formed by a curved steel plate embedded in concrete which fills the flange and plug portions of the lid to increase a load bearing capacity of the lid. 
     
     
       15. The system according to  claim 8 , further comprising an annular gasket seal on a bottom surface of the flange portion of the lid, the annular gasket seal sealably engaging the top end of the body portion of the storage container. 
     
     
       16. The system according to  claim 8 , wherein the flange and plug portions of the lid each comprise an outer steel structure filled with concrete for radiation shielding. 
     
     
       17. The system according to  claim 1 , wherein the body portion includes an inner shell, and outer shell, and an annular space between the shells fluidly coupled to the inlet vents and the storage cavity, the annular space defining a flow passage in which air flows from the inlet vents through the flow passage and into a bottom portion of the storage cavity of the storage container through openings in the inner shell. 
     
     
       18. The system according to  claim 17 , wherein the annular space is fluidly isolated from the at least one outlet vent in the lid. 
     
     
       19. The system according to  claim 1 , wherein the inlet vents extend through a peripheral sidewall of a flange portion of the lid, the flange portion having a diameter greater than the body portion of the storage container, and the at least one outlet vent extends through a plug portion of the lid having a smaller diameter than the body portion of the storage container. 
     
     
       20. A low profile system for below grade storage of spent nuclear fuel comprising:
 an array of storage containers, each of the storage containers comprising:
 an elongated body portion embedded in an engineered fill below grade, the body portion including a floor plate at bottom, an open top end, and a storage cavity extending between the floor plate and the open top end configured for holding a canister containing spent nuclear fuel; 
 a lid positioned above grade, the lid removably coupled to and enclosing the open top end of the body portion; 
 the lid comprising a plurality of air inlet vents and at least one air outlet vent, each of the vents forming a passageway from the cavity to ambient atmosphere; 
 
 a top concrete pad disposed on top of the engineered fill, an upper part of the body portion of each storage container being embedded in the concrete pad such that the open top end of the body portion is positioned adjacent a top surface of the concrete pad; 
 wherein the lid of each of the storage containers comprises a diametrically enlarged upper flange portion sealably engaging and radially overhanging the open top end of the body portion in a cantilevered manner, and a central lower cylindrical plug portion extending downwards from the flange portion, the plug portion being insertably received through the open top end of the body portion into the storage cavity; 
 wherein each of the storage containers is configured to draw air through the inlet vents which extend through the flange portion of the lid and into the storage cavity, the air being heated by the canister when emplaced in the storage cavity, the heated air flowing through the plug and flange portions of the lid via the at least one outlet vent to the ambient atmosphere; 
 wherein the inlet vents comprise a plurality of discrete circumferentially spaced peripheral openings formed in a sidewall of the flange portion of the lid; and 
 wherein the at least one outlet vent comprises a plurality of discrete air passageways each extending from a plurality of separate bottom openings in a bottom surface of the lid and converging at a common central opening extending through a top surface of the lid.